Maintenance Spray

What a general maintenance spray actually does

A maintenance aerosol is a multi-purpose product and it is worth being clear about which of its jobs it is good at.

It penetrates, creeping into a seized thread or a rusted joint. It displaces water, driving moisture off electrical connections, tools and metal surfaces. It protects, leaving a thin film that holds off corrosion. And it lubricates lightly, enough for a hinge or a latch.

The last one is where it is oversold. The film is thin and the carrier evaporates, so as a bearing or chain lubricant it needs reapplying constantly. For anything under real load or in a dusty environment, use a grease or a dry film lubricant and keep the maintenance spray for freeing, drying and protecting.

Used properly it is the most useful aerosol in a van. Used as the answer to everything it disappoints.

Getting a seized fitting apart

Penetrating a genuinely seized joint takes time, not force.

Apply, wait, apply again, and wait longer. Ten minutes does more than ten seconds and an overnight soak does more than either. Tapping the fitting while it soaks helps the fluid travel by vibration.

What does not help is reaching for a longer bar after one application. A sheared stud is a far larger job than a slow one, and the spray is cheap by comparison.

Masking spray

Masking spray does the opposite job to everything else on this page: it goes on to stop something sticking.

Sprayed onto a surface before painting or lining work, it dries to a peelable film. Overspray lands on the film, and the film comes off afterwards taking the overspray with it. No solvent, no scrubbing, no damage to the finish underneath.

On road marking, line painting and spray work around vehicles, glazing and street furniture, it turns a slow protection job into a quick one and removes the risk of damaging what you were protecting.

Using aerosols safely

Aerosols are pressurised and flammable, and the propellant is flammable even when the product is not.

Keep them out of direct sunlight and away from heat, never store them in a vehicle in summer or on a dashboard, and ventilate the area when spraying. Do not spray near hot work, and do not puncture or burn a can that seems empty.

Store upright, cap on. A cap missing means a nozzle full of dried product and a can that discharges somewhere unplanned.

Stock level

These are the products that get used on the awkward jobs, which are the ones that were not planned for.

A can in each van and a box in the store is the right shape. Running out of penetrating spray in front of a seized fitting is how a five minute job becomes an afternoon.

For greases and dry film lubricants, see lubricants.